A modern computing device, such as a personal computer, a smart phone, a game device, a handheld computer, a GPS device, and so on, includes a software operating system that allows the computer device to be controlled either directly by the user or by one or more application programs executing within the operating system.
Many operating systems and software applications employ graphical user interfaces (GUIs) to present information to users and to receive user input for controlling the behavior and functionalities of the underlying computing devices and/or application programs. A typical two-dimensional GUI of an operating system can be described as a “desktop” metaphor. Many software applications executing in the operating system can provide graphical objects, so-called “windows,” to present information content and various input control elements. Visually, a two-dimensional desktop of an operating system provides a background plane on which application windows provided by active software applications can be displayed.
Operating systems of the computing devices can often support multiple active applications at the same time, and each of the active applications can have multiple open windows concurrently presented on the desktop. Various schemes for managing the presentation and layout of open windows on the desktop have been proposed to improve the organization and navigation of the open windows.